The Warthog or Common Warthog (Phacochoerus africanus) is a wild member of the pig family (Suidae) found in grassland, savanna, and woodland in sub-Saharan Africa. The common name comes from the four large, wart-like protrusions found on the head of the warthog, which serve as a fat reserve and are used for defense when males fight. Afrikaans-speaking people call the animal vlakvark, meaning "pig of the plains".

A warthog is identifiable by the two pairs of tusks protruding from the mouth and curving upwards. The lower pair, which is far shorter than the upper pair, becomes razor sharp by rubbing against the upper pair every time the mouth is opened and closed. The upper canine teeth can grow to 10.0 in long, and are of a squashed circle shape in cross section, almost rectangular. A tusk will curve 90° or more from the root, and will not lie flat on a table, as it curves somewhat backwards as it grows. The tusks are used for digging, for combat with other hogs, and in defense against predators – the lower set can inflict severe wounds.

Warthog ivory is taken from the constantly growing canine teeth. The tusks, more often the upper set, are worked much in the way of elephant tusks with all designs scaled down. Tusks are carved predominantly for the tourist trade in East and Southern Africa.

The head of the warthog is large, with a mane down the spine to the middle of the back. Sparse hair covers the body. Its color is usually black or brown. Tails are long and end with a tuft of hair. Common warthogs do not have subcutaneous fat and the coat is sparse, making them susceptible to extreme environmental temperatures.

The warthog is the only pig species that has adapted to grazing and savanna habitats. Its diet is omnivorous, composed of grasses, roots, berries and other fruits, bark, fungi, insects, eggs and carrion.

Although capable of fighting (males aggressively fight each other during mating season) the warthog's primary defense is to flee by means of fast sprinting. The warthog's main predators are humans, lions, leopards, crocodiles, and hyenas. Cheetahs are also capable of catching warthogs of up to their own weight and raptors such as Verreaux's eagle owls and martial eagles sometimes prey on piglets. However, if a female warthog has any piglets, she will defend them very aggressively. On occasion, warthogs have been observed charging and even wounding large predators. Warthogs have also been observed allowing banded mongooses to groom them to remove ticks.